Chapter 10 Genetic Engineering Flashcards
What best describes a transgenic animal?
An animal whose chromosomes contain DNA from an external source
About 80% of the genes present in humans are also present in the mouse genome.
True
What term represents the hereditary information that it present in an animal?
Genome
What is a transgene?
The fragment of DNA that is introduced into the nucleus of a cell.
Barrier access to an animal room increases the risk of introducing disease entities to valuable genetically modified lines.
False
Whenever a dam experiences dystocia, oxytocin is effective at inducing labor.
False
A gene’s phenotype develops in utero and can always be observed after birth..
False: it can develop in utero and also during develop or adulthood
Overbreeding to obtain the number of mice needed with a particular genotype is unacceptable in a transgenic animal facility
False
If a large number of animals must be euthanized because of gene expression is inadequate, animal care staff may need emotional support.
True
Genetically modified mice have the same housing and nutrition needs as any other mice in the facility.
False
Every transgenic animal facility should have a mechanism for observing, documenting, and reporting health concerns regarding breeding or unique phenotypes.
True
With barrier access to a room, investigators must rely on animal care staff to handle all animal needs.
True
What might affect transgenic mice and the success of their breeding?
Noise, odors, and lighting
Females with a litter from implanted fertilized eggs are called:
Surrogate mothers
What is an initial observation indicating successful mating?
Vaginal plug
In the production of gene-targeted animals, mating with a stud makes the recipient female pseudopregnant.
False
Placing pups with a female other than the one who gave birth to them is called cross-fostering.
True
If fertilized eggs are required, along with egg donor females, what animals are required?
Stud males
Embryos can be transferred to recipient mice surgically if the embryos are at least 3.5 days old.
False: Embryos can be transferred to recipient mice surgically only if the embryos are less than 3.5 days old.
Pronuclear injection provides the scientist with a more specific tool than gene-targeted mutation for placement of the transgene.
False
To construct a transgene, the scientist must start with an existing piece of DNA that originated in a living organism.
False
A transposon is a DNA sequence obtained from bacteria.
True
Pronuclear injection introduces a transposon-flanked DNA sequence with an enzyme that inserts multiple copies of the DNA into the genome.
False: a single copy
PCR can be used to genotype an animal born after pronuclear injection of a transgene.
True
If a transgene is intergrated in one of the chromosomes of a pair, the animal is said to be:
hemizygous
What best describes “alleles”?
Copies of the same gene
Wild-type animals are more commonly used to start a transgenic line because it is easier to observe a phenotype change than in inbred strains.
False: inbred strains are used because a phenotypic change is easier to see.
All animals produced by pronuclear injections of the same transgene have the same phenotype.
False
Offspring of two hemizygous parents inherit at least a copy of the transgene.
False: in theory, 25% of the offspring will have NO copy of the transgene.
Eukaryotic cells have the ability to develop into any kind of cell in the body.
False: embryonic stem cells.
CRISPR is an engineered DNA identification mechanism.
False: CRISPR is a naturally occurring DNA identification mechanism
The gene-targeted mutation derived from the injected embryonic stem cells is always present in the sperm of a male chimera.
False
To test for germline transmission, chimeras are mated to animals of the same strain from which their ES cells were derived.
False: Chimeras are mated to animals of the same strain as the blastocyst host.
Using engineered systems for gene targeting eliminates the need for embryonic stem cell culture
True
Mouse models have been developed hat replace the mouse immune system with a human system.
True
What is a genetically engineered animal that has had one or more genes from its genome functionally removed?
Knockout
Embryonic stem cells used for gene-targeted mutations are grown in the presence of antibiotics.
True
CRISPR/Cas9 may be used to selectively knock out genes of interest.
True
In genetically engineered mice known as knockouts, the transngene of interest is functional.
False
Tail biopsies on adult mice should be done under anesthesia.
True
What test might be used to assess the phenotype of mutant animals?
Imaging techniques
Neurological test
Behavioral test
In order to avoid disturbing the litter, the best time to genotype a mouse is within two days of birth.
False: the best time is around weaning time
The phenotype of mutant animals indicates the engineered change in the DNA
True
Backcrossing founders to wild-type animals can be used to:
- Ensure germ lines transmission of an induced mutation
- Cross a hybrid with one of its parents
- move a gene generated in one inbred strain to another.
Cryopreservation can be used to store frozen embryos, and subsequently recover the original genetic make-up of a mouse line when genetic drift has caused changes in the strain.
True
The Mutant Mouse Regional Resource Centers serve as a centralized repositories for many mouse lines.
True
What techniques allows a mouse strain to be taken “off the shelf” but still be available for use when needed?
Crypreservation
Sperm cryopreservation is a terminal procedure.
True
What is the goal of genotyping?
To determine if a specific DNA fragment is present in the genome of an organism.
Best describes genetic engineering?
Manipulating DNA molecules to alter their composition.
Using the pronuclear injection technique, what is the average percentage of offspring carrying the transgene?
20%
What is the best way to describe genetic engineering?
Manipulating DNA molecules to alter their composition
What is a transgene?
The fragment of DNA that is introduced into the nucleus of a cell
Using the pronuclear injection technique, what is the average percentage of offspring carrying the transgene?
20%
If a transgene is integrated in one of the chromosomes of a pair, the animal is said to be:
hemizygous
What best describes a congenic strain?
The result of backcrossing for 10 generations
